Methods and devices for blood vessel harvesting

ABSTRACT

Methods and devices for harvesting veins from the body. The methods and devices allow vein harvesting using laparoscopic procedures. A working space is created over the vein using standard laparoscopic procedures and a side-hooked wire is inserted into the working space and twisted to insert the side-hook under the vein. The wire is then pulled or drawn along the vein to separate the vein from the surrounding tissue. In an alternative embodiment, vein separation is accomplished by threading a soft rubber tube under the vein, grasping the ends of the tube so as to surround the vein, and then pulling the tube along the vein. In other embodiments, the working space is created with everting balloons.

This application is a continuation of U.S. application Ser. No.10/244,330, filed on Sep. 16, 2002 now U.S. Pat. No. 6,840,946, which isa continuation of U.S. application Ser. No. 09/520,308, filed on Mar. 7,2000, now U.S. Pat. No. 6,451,035, which is a continuation of U.S.application Ser. No. 09/236,266, filed on Jan. 22, 1999, now U.S. Pat.No. 6,068,639, which is a continuation of U.S. application Ser. No.09/145,148, filed on Sep. 1, 1998, now U.S. Pat. No. 5,899,913, which isa continuation of U.S. application Ser. No. 08/991,425, filed on Dec.15, 1997, now U.S. Pat. No. 5,853,417, which is a continuation of U.S.application Ser. No. 08/475,137, filed on Jun. 7, 1995, now U.S. Pat.No. 5,730,748, which is a continuation of U.S. application Ser. No.08/444,424 filed on May 19, 1995, now U.S. Pat. No. 5,601,581. Thepriority of these prior applications is expressly claimed and theirdisclosures are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to methods and devices for endoscopic surgery, inparticular to methods and devices for dissecting tissue to create aworking space for endoscopic instruments.

BACKGROUND OF THE INVENTION

Numerous surgical procedures have been developed to replace arteriesthat have become blocked by disease. The aortocoronary bypass surgery isperhaps the most important of these bypass operations. The coronaryarteries supply blood to the heart. As a result of aging and disease,coronary arteries may become blocked by plaque deposits, stenosis, orcholesterol. In some instances, these blockages can be treated withartherectomy, angioplasty or stent placement, and coronary bypasssurgery is not required. Coronary bypass surgery is required when theseother methods of treatment cannot be used or have failed to clear theblocked artery. In the coronary bypass surgery, a vein is harvested fromelsewhere in the body and grafted into place between the aorta and thecoronary artery beyond the point of blockage.

The coronary bypass surgery requires a length of vein or artery for thegraft. It is preferred to use a vein taken from the patient undergoingthe bypass surgery. The patient is a ready source of suitable veins thatwill not be rejected by the body after transplantation and grafting ontothe aorta and coronary artery. The saphenous vein in the leg is the bestsubstitute for small arteries such as the coronary arteries, and it isthe preferred vein for use in coronary bypass surgery. This is becausethe saphenous vein is typically 3 to 5 mm in diameter, about the samesize as the coronary arteries. Also, the venous system of the legs issufficiently redundant so that after removal of the saphenous vein,other veins that remain in the leg are adequate to provide adequatereturn blood flow. The cephalic vein in the arm is an alternative thatis sometimes used.

In a typical operation previously required to harvest the saphenousvein, the surgeon cut into the leg to allow access to the saphenous veinand cut the vein from the leg. To expose the vein, the surgeon makes aseries of incisions from the groin to the knee or the ankle leaving oneor more skin bridges along the line of the incisions. (Some surgeonsmake one continuous incision from the groin to the knee or ankle).Handling of the vein must be kept to a minimum, but the vein must beremoved from connective tissue that requires some force to remove. Afterexposing the vein, the surgeon grasps it with his fingers whilestripping off the surrounding tissues with dissecting scissors or otherscraping instruments. The surgeon uses his fingers and blunt dissectiontools to pull and lift (or mobilize) the vein from the surroundingtissue. The vein is mobilized or pulled as far as possible through eachincision. To reach under the skin bridges, the surgeon lifts the skinwith retractors and digs the vein free. While stripping the vein, thesurgeon will encounter the various tributary veins that feed into thesaphenous vein These tributaries must be ligated and divided. To divideand ligate tributaries that lie under the skin bridges, the surgeon mayneed to cut one end of the saphenous vein and pun it under the skinbridge to gently pull the vein out from under the skin bridge until thetributary is sufficiently exposed so that it may be ligated and divided.When the vein has been completely mobilized, the surgeon cuts theproximal and distal ends of the vein and removes the vein from the leg.After removal, the vein is prepared for implantation into the graftsite, and the long incisions made in the leg are stitched closed.

The procedure described above can be used to harvest veins for a femoralpopliteal bypass, in which an occluded femoral artery is bypassed fromabove the occlusion to the popliteal artery above or below the knee. Theprocedure can also be used to harvest veins for the revascularization ofthe superior mesenteric artery which supplies blood to the abdominalcavity and intestines. In this case, the harvested vein is insertedbetween the aorta to the distal and patent (unblocked) section of themesenteric artery. For bypass grafts of the lower popliteal branches inthe calf, the procedure can be used to harvest the umbilical vein. Theharvested vein can also be used for a vein loop in the arm (fordialysis) between the cephalic vein and brachial artery. The proceduresmay be used also to harvest veins for femoral-tibial, femora-peroneal,aorto-femoral, and iliac-femoral bypass operations and any other bypassoperation.

As can be seen from the description of the harvesting operation, theharvesting operation is very traumatic in its own right. In the case ofcoronary artery bypass, this operation is carried out immediately beforethe open chest operation required to graft the harvested vein into thecoronary arteries. The vein harvesting operation is often the mosttroublesome part of the operation. The long incisions created in the legcan be slow to heal and very painful. Complications resulting from thevein harvesting operation can also hinder the patient's recovery fromthe entire operation.

The method of vein harvesting presented herein is accomplished withendoscopic procedures. This allows the veins to be harvested in anoperation that requires only a few small incisions. Endoscopic surgicaltechniques for operations such as gall bladder removal and hernia repairare now common. The surgeon performing the operation makes a few smallincisions and inserts long tools, including forceps, scissors, andstaplers into the incision and deep into the body. Viewing the toolsthrough an endoscopic laparoscope, or a video display from theendoscope, the surgeon can perform all the cutting and suturingoperations necessary for a wide variety of operations. The proceduresare also referred to as laparoscopic surgery, minimally invasivesurgery, or video-assisted surgery. References to endoscopic surgery andendoscopes below is intended to encompass all these fields, and alloperations described below with reference to endoscopes can also beaccomplished with laparoscopes, gastroscopes, and any other imagingdevices which may be conveniently used.

Minimally invasive procedures for vein removal have been proposed.Knighton, Endoscope and Method for Vein Removal, U.S. Pat. No. 5,373,840shows a method of cutting the saphenous vein at one end, and graspingthe vein with graspers or forceps, then sliding a ring over the veinwhile holding it. Knighton uses a dissecting tool with an annularcutting ring, and requires that the saphenous vein be overrun orprogressively surrounded with the dissecting tool and the endoscope, sothat after the endoscope has been inserted as far as it will go, theentire dissected portion of the vein has been pulled in the lumen of theendoscope. As shown in FIGS. 1 and 10 of Knighton, the method requiresdeployment of the forceps inside the annular dissection loop, and itrequires deployment of the loop and graspers inside the endoscope lumen.The blood vessel must be cut and grasped by the forceps before it can bedissected by the dissecting ring.

The method of vein harvesting presented below may use a balloon toassist in dissecting the harvested vein. An everted balloon storedinside a cannula or trocar may be inserted through one of the smallincisions and inflated so that it everts out the end of the cannula andforces its way along the vein to create a tunnel. Endoscopic balloonshave been used for retraction and dissecting in other applications, butnot for dissection and tunneling for harvesting blood vessels.Kieturakis and Mollenauer, Apparatus and Method for Developing anAnatomic Space for Laparoscopic Procedures with LaparoscopicImplantations, U.S. Pat. No. 5,540,791 shows a balloon designed toseparate the peritoneum from the overlying fascia (skin, fat, andconnective tissue). This creates a working space for laparoscopic repairof hernias. The balloons described below provide additional fees makingit suitable for use in endoscopic or laparoscopic vein harvesting.

It is an object of the inventions presented herein to provide methodsand devices for harvesting veins with a less traumatic operation thanthe operations presently used to harvest veins.

SUMMARY OF THE INVENTION

The methods and devices presented herein allow surgeons to harvest veinswithout making the long incisions previously required. The procedure isa minimally invasive procedure that requires just a few small incisions,one at either end of the saphenous vein. The procedure is accomplishedwith endoscopic or laparoscopic instruments under the guidance of anendoscope. The surgeon makes one small incision at each end of thesaphenous vein. After making the incisions, the surgeon inserts atunneling instrument or blunt dissector into one incision and advancesor pushes along the saphenous vein to make a small tunnel along thesaphenous vein. The surgeon then inserts the long balloon describedbelow in the tunnel and inflates the balloon to enlarge and furtherpropagate the tunnel. The surgeon may use the balloon to dissect the fatand skin overlying the saphenous vein away from the vein, and also toenlarge the tunnel to an appropriate size. When the tunneling iscompleted, the surgeon removes the balloon and seals the tunnel at bothends. The surgeon then injects carbon dioxide, nitrous oxide, or othersuitable gas into the tunnel at sufficient pressure (typically 5-15mmHg) to inflate the tunnel and create room for laparoscopicinstruments. The surgeon then inserts an endoscope or laparoscopethrough the seal to provide a view of the procedure, and inserts anendoscopic vein harvesting device described in detail below. With thevein harvester in place, the surgeon manipulates the vein harvester tostrip the connective tissue from the vein, identify and cut sidebranches, and remove the vein from its channel in the leg. After thevein is loosened or dissected free from its channel in the leg, thesurgeon can cut the proximal and distal ends and easily pull the veinfrom the leg. The small skin incisions are stitched so they may heal.The small incisions heal much more readily, with fewer complications andfar less pain, than the operation now in use.

The surgeon operating with the vein harvesting device has a choice oftunneling instruments. A typical blunt dissection is performed with along stiff rod with a round tip, and the tip may be enlarged. Thesurgeon may also use a device referred to as a peanut, which is long rodwith a soft fabric or foam tip. These devices are used to create a smalltunnel, and then the balloon dissector may be inserted to enlarge thetunnel. The balloon dissector described below allows the tunnelingoperation to be accomplished by the balloon, thus allowing easier andless traumatic creation of the initial tunnel and also permitting thesurgeon to create the enlarged tunnel with this single device. Thedevice may be used as an alternative to the other methods of enlargingthe tunnel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the leg showing incisions necessary for harvestingthe saphenous vein using the methods presented herein.

FIG. 2 shows the balloon dissector with the balloon housed in thehandle.

FIG. 3 shows the balloon dissector with the balloon in its inflatedstate.

FIG. 4 shows the balloon cannula with the balloon fully inflated.

FIG. 5 shows a cross section of the inflatable membrane in itsuninflated state.

FIG. 6 shows a cross section of the inflatable membrane in its inflatedstate.

FIG. 7 shows a cross section of a simplified balloon cannula.

FIG. 8 shows the balloon cannula inserted in the leg of a patient.

FIG. 9 shows a balloon dissector with a thru-lumen.

FIG. 10 shows the balloon dissector with thru-lumen with the balloonfully inflated.

FIG. 11 shows an alternative embodiment of the balloon dissector with athru-lumen.

FIG. 12 shows a hooked vein harvester.

FIGS. 13 and 14 show a double-hooked vein harvester.

FIG. 15 shows a tube harvester.

FIGS. 16-18 are laparoscopic views of the hooked vein harvester beingplaced around the saphenous vein.

FIG. 19 shows the hooked vein harvester tool fitted with sealing tubesfacilitating its use during insufflation.

DETAILED DESCRIPTION OF THE INVENTION

The methods and devices presented herein take advantage of laparoscopicprocedures to lessen the trauma of vein harvesting operations. Insteadof making an incision along or over the entire length, or essentiallythe entire length of the vein to be harvested, the procedure may beconducted with only a few small incisions. All that is needed is aworking space large enough to allow the surgeon to use the tool and viewthe operation through a laparoscope. In the preferred embodiment of themethod, the surgeon creates a working space under the skin and over thesaphenous vein using laparoscopic techniques. The surgeon makes severalsmall incisions to expose the saphenous vein. These incisions arereferred to as cut-downs. A distal incision near the knee and a proximalincision at the groin are preferred. If the entire length of thesaphenous vein is to be harvested, an additional incision can be madeclose to the ankle. The saphenous vein can be seen through thecut-downs. It will be apparent from the description that the use ofthree or four incisions used to harvest the entire saphenous vein aremerely a matter of convenience, and those particularly skilled inlaparoscopic procedures may require fewer incisions, and also more smallincisions may be required.

After incision, the surgeon inserts a blunt tunneling tool (not shown)into one incision and pushes it along the saphenous vein towards theother incision. The tunneling creates a tunnel or channel running alongthe saphenous vein. The tunnel may be expanded by insertion of theballoon described herein, which can be inflated to expand or propagatethe tunnel further along the saphenous vein.

FIG. 2 shows the balloon dissector or balloon trocar 15 in itsuninflated state, with the balloon packed inside the device. The balloon16 is a non-elastomeric balloon or bladder. The balloon trocar 15comprises a balloon 16, a trocar portion 17 and a balloon housingportion 18. The trocar portion 17 is cylindrical, with a circular crosssection, but may be made in oval cross section or in other crosssections. The balloon 16 is sealed to the distal tip 19 of the trocarportion 17 of the balloon trocar 15. The balloon material is wrappedover the distal tip 19 and sealed to the outside of the trocar portion17. The balloon 16 may be sealed to the trocar 15 with adhesives, or itmay be heat sealed, banded or taped (cellophane tape, such as SCOTCH™adhesive tape, is sufficient) or sealed in any suitable manner to thetrocar. The balloon 16 then extends back through the trocar, to theproximal balloon housing portion 18 of the balloon trocar 15. When usedfor tunneling along the saphenous vein, the balloon is approximately 60centimeters long. The trocar or cannula is most conveniently 10-20centimeters long, so that the excess length of the balloon is folded asshown inside the balloon housing portion of the balloon trocar. Theballoon is sealed at its distal end 20, referring here to the distal endas determined when the balloon is everted outside of the balloonhousing. The balloon may be formed by extrusion or by heat sealing orgluing a number of pieces of material together.

The balloon trocar 15 is fitted with an inflation port 21, which may belocated anywhere on the trocar portion 17 or balloon housing 18. In FIG.2, the inflation port is shown affixed to the balloon housing at itsproximal end near the neck-down portion 22 between the balloon portionand the trocar portion. The inflation port comprises a tube establishinga pathway for liquid or gas to be injected into the balloon trocar toinflate the balloon. A convenient length of flexible tubing such astygon tubing 23 can be used to connect the balloon to a bladder pump 24or large syringe capable of injecting liquid or gas into the balloonhousing. Sterile saline solution is the preferable inflation medium formedical applications. Alternately, air, CO₂, or even foam or othersubstances may be injected to cause inflation.

Upon injection of liquid or gas into the balloon housing, the pressurecreated inside the housing forces the balloon to evert out through thetrocar portion of the balloon. The segment of the balloon stored in thehousing portion gradually rolls forward (distally) and outside thetrocar, rolling over itself and turning itself inside out, or everting,and pushing forward. As shown in FIG. 3, the balloon has everted underpressure, and the leading edge 25 pushes forward, unrolling from theinside, and advances through body tissue. Eventually the ballooncompletely unfolds or everts to create a long cylindrical balloon. Theballoon may be folded in a variety of ways, including the fan fold shownin FIG. 3 or with accordion folds, as shown in FIG. 9, or it may berolled inside the cannula.

The fully inflated and everted balloon is shown in FIG. 4. The inflateddiameter of the balloon is more useful when it is larger than thediameter of the trocar. This allows for the creation of a tunnel that iswider than the trocar. The balloon diameter or radial cross section ofthe balloon may also be smaller than the diameter of the trocar, and maybe adjusted to create a tunnel of any desired size. The balloon may bepleated, or folded like a brown paper bag, or folded in any other mannerwhich facilitates eversion and packing in the housing. The cross sectionof the uninflated balloon along section a of FIG. 3 is shown in FIG. 5,and the cross section of the inflated balloon along cross section b ofFIG. 4 is shown in FIG. 6. The balloon is preferably non-elastic, sothat it will not expand uncontrollably into the softest body tissue orweakest tissue plane. Acceptable materials include polyethylene andother medical grade plastics. A slight degree of elasticity isacceptable, and even complete elasticity may be acceptable where thereis no danger of the balloon expanding in an unwanted or unpredictableshape.

FIG. 7 shows an alternate embodiment of the balloon trocar in which theexcess length of the balloon is stored inside a longer housing so thatit need not be folded. The balloon housing 18 is longer than the balloonhousing 18 shown in FIG. 2. The balloon is sealed at the distal tip ofthe trocar in the same manner shown in FIG. 2, and the distal end of theballoon is sealed. The inflation port 21, again, may be placed in anyconvenient place on the balloon trocar. The proximal end of the balloonhousing is sealed by an end cap 27, which can be integrally formed withthe balloon trocar. The end cap can also be removable and include athreaded cap which is screwed onto the end of the balloon housing andfitted with a gasket to prevent leakage. The end cap can also include aplug 28 which fits tightly into the balloon housing, and the plug may beprovided with an O-ring 29 to help maintain the seal on the housing.Upon inflation, the balloon everts or unfolds out the distal tip of theballoon trocar. The balloon forces itself between the body tissues to bedissected or tunneled through in the same manner as describe above.

FIG. 8 shows the balloon trocar inserted into the ankle incision or cutdown 13. The surgeon inserts the balloon into the incision and points itin the direction of the tunnel that he wants to make. In theillustration, the balloon trocar is inserted as it would be if thesurgeon wanted to create or enlarge a tunnel along the saphenous vein,going up the leg. Once the surgeon has put the balloon trocar in place,the balloon is ready for inflation. The surgeon can inflate the balloonand allow it to evert into the leg. The balloon will follow a tunnelpreviously created by the surgeon with a blunt dissecting tool, if thesurgeon has chosen to create the tunnel with another tool and use theballoon to enlarge that tunnel. The balloon will also create its owntunnel, without the need to create an initial tunnel over the entirelength of the saphenous vein. The surgeon can make a small startertunnel, using a finger or tool to get the tunnel started, then thesurgeon can insert the balloon and inflate it. Upon eversion orunrolling, the balloon will force its way into the leg and propagatealong the tissue boundary between the saphenous vein and the fat andskin layer above the vein. Eversion and propagation of the ballooncreates a tunnel over the saphenous vein, or, in medical terms, superiorto the saphenous vein. As the balloon propagates along the vein, itraises the skin over the balloon, creating a bubble or blister 30 whichindicates that the balloon is everting along the vein, and has not takensome errant course. As the balloon propagates up the leg, the surgeonmay guide it by pushing the tip of the balloon with his finger, throughthe skin without puncturing the skin. In this manner, the balloon gentlyforces its way between the layers of body tissue and pushes them apartto form the enlarged tunnel necessary for endoscopic or laparoscopicsurgery on the saphenous vein.

The balloon dissector can be used in other procedures besides dissectionfor vein harvesting, and its description in that environment is intendedto be illustrative of the device. The device can be used in anyprocedure for dissection, separating or retracting body tissue. Theballoon trocar may be made in varying sizes and lengths, so that it canbe used to create passageways for laparoscopic surgery. After thepassage is created, whether by the balloon or other means, the balloontrocar may be used to hold passageways open to allow laparoscopicinstruments to be used in front of the distal end or leading edge of theeverting balloon. These instruments may be inserted through thethru-lumen of the balloon trocar, or they may be inserted through otheraccess ports so that the balloon is used only to hold body tissue out ofthe way of these instruments as they are used. Additionally, the devicemay be used to hold an endoscope or laparoscope in a fixed and stableposition within the body, so that the video display which the surgeonwatches remains stable.

As described above, the balloon trocar is used for dissection ortunneling in a semi-blind manner. When used in the leg, the propagationof the balloon can be observed by watching skin rise as the balloontunnels under the skin. Because the location of the saphenous vein iswell known and its exact course through the leg can be readilydetermined, the surgeon can be sure that the balloon is following theintended path along the saphenous vein. In some cases, however, thesurgeon may wish to observe the propagation of the balloonendoscopically or the surgeon may wish to observe various structures asthe balloon everts past the structures. The everting balloon with athru-lumen depicted in FIG. 9 can be used in this instance.

As shown in FIG. 9, the balloon trocar 15 may be constructed to allowpassage of an endoscope 31 or other instrument through the balloon. Theballoon housing 18 and trocar portion 17 of the device may be similar tothe comparable structures shown in FIG. 2. The balloon is sealed to thedistal tip of the trocar portion, and is also sealed to the proximal endof the balloon housing by sealing the balloon the sliding piston seal orsliding plunger 32. The sliding piston seal fits tightly against theinside of the balloon housing to create an air tight seal. A guide tube33 is provided attached to the sliding piston to facilitate sliding theendoscope through the through lumen. Alternatively, in the configurationshown in FIG. 11, the balloon comprises a tube of non-elastic materialwith a short length of cuff rolled back at each end and folded over theproximal edge and sealing it to the outside of the balloon housing. Theballoon housing may be provided with an end cap 27 to prevent backwardeversion of the balloon, and the end cap may be provided with a port 34which accommodates the endoscope. Any other suitable sealing means maybe used. FIG. 10 shows the balloon in its fully extended state with thelumen large enough for an endoscope to be inserted through the inside ofguide tube or mandril 33. With the balloon inflated or deflated, anendoscope can be inserted through the thru-lumen 35, as shown in FIGS. 9and 10.

Before the balloon is inflated to cause eversion which is used fortunneling or dissection or retraction of body tissue, it is foldedaccordion style inside the balloon housing portion of the balloontrocar. The excess length is held inside the housing in this manneruntil the balloon is everted under pressure. The accordion folds 36 canbe made without a mandril, as shown in FIG. 11, or with a mandril 33 asshown in FIGS. 9 and 10. Alternatively, the endoscope or otherinstrument used within the lumen may be used as the mandril. The mandrilcan be integral with the end cap, or it can be mounted on a fixed orsliding plunger, annular seal, sealing ring or piston seal 32. Provisionof a sliding plunger allows longer deployment of the balloon outside thetrocar portion.

While in use, the balloon may be inflated and everted partially or fullyto cause it to tunnel through body tissue or between tissue planes.During eversion, the endoscope can be advanced to the leading edge oreverted distal end of the balloon so that the surgeon can view the bodytissue as it is dissected.

Insufflation

When the tunnel is of sufficient size, the incisions may be sealed withround trocars 37 and 37 a, shown in place in FIG. 1. The trocars areused to insert the various tools used in the procedure. One trocar isused to inject or infuse carbon dioxide (CO2) or other gas (or liquid)into the tunnel in a procedure known as insufflation, which pressurizesthe tunnel and keeps it open and expanded to make it easier to seeinside the tunnel and easier to insert and manipulate an endoscope andinstruments into the tunnel. Insufflation is accomplished withtechniques generally known to endoscopic and laparoscopic surgeons. Ascan be seen in FIG. 1, the insufflation creates an inflated space 38under the skin. An endoscope or laparoscope 16 is inserted into one ofthe trocars 37 or 37 a, and is shown in FIG. 1 inserted into the groinincision 13 through trocar 37 a. The endoscope permits the surgeon toview the tunnel, including the saphenous vein and connective tissue. Theendoscope fits tightly into the trocar so a seal is accomplished betweenthe endoscope and the trocar, and this helps maintain the pressure ofthe CO₂ gas. Also during insufflation, the vein harvesting tool may beinserted through the ankle trocar and operated to dissect and strip thevein and mobilize it. The incision may optionally be made at the knee,as indicated at item 12, or may be made at both the knee and the ankleso that the balloon dissecting devices and vein harvesting devices canbe used to dissect the saphenous vein first in the thigh and then in thecalf, or vice-versa.

FIG. 12 shows a hooked vein harvesting tool 39 particularly suited foruse in the method. The hooked vein harvesting tool 39 comprises a shaftor long slender rod 40 of stiff wire with a grip 41 on one end and asideways hook 42 on the end. The hooked vein harvester may be made ofstainless steel, plastic, or other biocompatable material such asnitinol. The long segment or shaft 40 may have an offset or crookedsegment 43 to set the hook off the axis established by the shaft. Thesideways hook 42 is generally perpendicular to the axis of the shaft,or, in other words, the plane in which the hooks lies perpendicular tothe line established by the shaft or crooked section. Of course, thehook need not be exactly perpendicular, and maybe set at any angle whichfacilitates the ability to use the hook as described herein. By twistingor rotating the shaft 40, the surgeon can slip the hook under theexposed saphenous vein. The hook 42 may be provided with a pointed tipto enable it to puncture the connective tissue which covers thesaphenous vein. The hook occupies an arc or radial segment of about 180°to 270° so that the saphenous vein will lie inside the hook when engagedby the hook. The diameter of the circle defined by the hooked isslightly larger than the diameter of the saphenous vein, so that thehook can be easily slipped under the saphenous vein. When the hook 42 issafely around the saphenous vein, the surgeon can separate the vein fromthe surrounding tissue by pulling or pushing the shaft and sliding thehook along the saphenous vein. When a side branch is encountered, thehook will be blocked by the side branch, and can be used to expose theside branch for ligation and dividing it from the saphenous vein. Whenthe entire length of the saphenous vein has been separated from theconnective tissue, the vein can be grasped with laparoscopic grippersand pulled from the leg through the groin incision 13, the knee incision12 or the ankle incision 14.

FIGS. 16-18 show the use of the hooked vein harvester 39 as viewedthrough an endoscope inserted through the groin incision 11. Thesaphenous vein 6 is seen lying in its channel surrounded by connectivetissue 44. The hooked vein harvester 39 is shown as it would appear wheninserted from the knee incision 12. The hook 42 appears in theforeground and the shaft 40 is receding toward the far end of thetunnel. In FIG. 16, the hook 42 is in position at the upper end of thesaphenous vein. In FIG. 17, the shaft has been twisted or rotated by thesurgeon so that the hook is slipped under and round the saphenous vein.In FIG. 18, the surgeon has pulled the vein harvester, and perhapsrotated the hook a bit more and pulled again, and freed or dissected thesaphenous vein from the connective tissue. The shaft can be manipulatedto lift or mobilize the saphenous vein from the channel in which itlies. The shaft can be pushed and pulled as necessary to separate ordissect the connective tissue from the vein. Several other features ofthe device are provided in order to make it more suitable for use inconjunction with the trocar and the CO₂ insufflation. These featuresmake it easier to deploy the vein harvester through a standard trocarwith an inside diameter that is larger than the wire 40. As shown inFIG. 19 a tube 45 surrounds the wire 40 for tie greater portion of itslength. At the distal end of the tube, an O-ring 46 or plastic sealingring is fixed to the inside of the tube and fits closely around theshaft or wire 40. This seal helps maintain the CO₂ pressure inside thetunnel so that the tunnel remains inflated or insufflated while the veinharvester is in use. At the proximal end of the tube 45, a valveassembly 47 with a duckbill valve 48 inside fits tightly into the tube45. The valve assembly allows the wire to pass through the duckbillvalve 48, and the duckbill valve closes around the wire to provide anadditional seal around the wire. A second O-ring or plastic sealing ringcan also be used to provide a second seal at the proximal end of thetube. To make handling of wire easier, a handle 49 can be provided onthe proximal end 41 of the wire. The handle shown in FIG. 19 isremovable, but a fixed handle may be provided.

The saphenous vein has a number of tributary veins that carry venousblood into it. These tributaries must be tied off and cut off of thesaphenous vein before the saphenous vein can be removed. In medicalterms, these tributaries must be ligated and divided. These tributariescan be readily identified with the vein harvester because the surgeonwill feel the resistance while pulling and will not be able to pull thehook through a tributary vein. When a tributary is encountered, thesurgeon can use standard endoscopic and laparoscopic tools to close thetributaries and cut them from the saphenous vein. The tributaries can beseparated from the vein after the entire vein is stripped, or thesurgeon may choose to separate them as they are encountered.

FIG. 13 shows a double hooked vein harvester 51 with the same shaft 40and hook 42 at the distal end of the shaft, and a second hook 52 fixedto the shaft just a short distance before the hook 42 which is fixed atthe extreme end of the shaft. This end of the shaft is referred to asthe distal end because it is end that is inserted into the body. (Thehandle end which remains outside the body is referred to as the proximalend.) The second hook 52 is located a short distance proximal of thefirst hook 42 which is located at the distal tip of the shaft 40. Theproximal hook or second hook 52 opposes the first hook or distal hook42, and extends from the shaft along a plane perpendicular to the shaft.Where the first hook extends counterclockwise from the rod, the secondhook extends clockwise from the rod so that the two hooks are inopposing relationship. The hook need not be exactly perpendicular, andneed only be offset to a degree sufficient to allow it to engage thesaphenous vein upon rotation toward the vein.

The double hooked vein harvester 51 is used in much the same manner asthe hooked vein harvester 39. The first hook 42 is slipped under thesaphenous vein and rotated fully so that the second hook 52 can beslipped over the saphenous vein, so that the vein is more fullysurrounded by the hooks. The hooks can be made long enough to fullyencircle the vein. In this case, tributary veins will obstruct theproximal hook or second hook 52 when it is pulled. When obstructed, theshaft can be rotated until the second hook is no longer obstructed bythe tributary vein, and pulled until the second hook passes thetributary. The tributary will then block the distal hook, and can bepassed by again rotating the shaft back to its original position untilthe distal hook is no longer obstructed, and the shaft 40 can be pulleduntil the distal hook 42 passes the tributary. Alternatively, the hookscan be made short enough so that they do not completely encircle thevein. In this manner, the hooks can be pulled more safely past tributaryveins because a radial segment will remain open between the hooks. Analternative embodiment of the double hooked vein harvester may have bothhooks located at the same point on the shaft and opposing each other, asshown in FIG. 14.

Another device for vein harvesting is shown in FIG. 15. A soft plasticor rubber tube 53 is threaded under the saphenous vein using standardlaparoscopic instruments such as laparoscopic forceps and a hookedsuturing needle (not shown). After the tube has been threaded around thevein, the surgeon grasps both ends in a laparoscopic grasper 54. Withthe tube grasped close to the vein so that it surrounds the vein, thesurgeon can pull the tube along the vein to separate the vein from itsconnective tissue and lift it from its channel. Tributaries are detectedwhen the surgeon feels more resistance to pulling on the tube. The tubemay be made of any material which is pliant enough to thread around thevein and pulled along the vein without injuring the vein.

Some of the advantages of the vein harvester may be beneficial duringopen surgery, as well as endoscopic vein harvesting.

The device and method described above has been developed in the field ofvein harvesting and vascular surgery. However, it is readily apparentthat the devices and methods may be used for dissecting and mobilizingother long organs of the body. Various arteries and veins must bedissected and mobilized for other operations, such as popliteal bypass,or a dialysis vein loop. In these operations, a vein must be harvested,and the sites at which the vein will be attached or amostosized mustalso be uncovered. The balloon dissector may also be used to gain accessto any blood vessel for any type of vascular surgery. For example, thedevice and method described above has been developed in the field ofvein harvesting and vascular surgery. However, it is readily apparentthat the devices and methods may be used for dissecting and mobilizingother long organs of the body. The balloon dissector may also be used togain access to any blood vessel for any type of vascular surgery.

The vein harvesting devices shown above may be made with a variety ofmaterials. The methods shown may be applied to harvesting veins orarteries other than the saphenous vein and other veins mentioned above,and may be employed for harvesting veins for transplant into any area ofthe body. Where appropriate, the devices and methods may be used duringopen surgery to facilitate the removal of veins or arteries, in whichcase the working space is provided by the normal open surgerytechniques. While the preferred embodiments of the devices and methodshave been described, they are merely illustrative of the principles ofthe invention. Other embodiments and configurations may be devisedwithout departing from the spirit of the inventions and the scope of theappended claims.

1. A method of harvesting a section of an artery from a body comprisingthe following steps: providing a dissection cannula having a lumen andan endoscope inserted into said lumen; inserting said dissection cannulathrough an incision in the body; advancing said dissection cannulaalongside the artery to dissect with said dissection cannula to create aspace in body tissue, the space being at least partially occupied bysaid dissection cannula; viewing via said endoscope; providing adissection tool separate from said dissection cannula; and dissectingsurrounding tissue from the artery by moving the dissection tool alongthe artery.
 2. The method of claim 1 wherein said dissection cannulafurther comprises a balloon and said balloon is inserted into the bodyand inflated to cause additional dissection over that caused by thedissection cannula.
 3. The method of claim 2 wherein said balloon isinverted and inflating said balloon causes said balloon to evert andadvance along the artery.
 4. The method of claim 1 further comprisingthe step of ligating and dividing side branches from the artery.
 5. Amethod of harvesting a section of an artery from a body comprising thefollowing steps: providing a dissection cannula having a lumen and anendoscope inserted into said lumen; inserting said dissection cannulathrough an incision in the body; advancing said dissection cannulaalongside the artery to dissect with said dissection cannula to create aspace in body tissue, the space being at least partially occupied bysaid dissection cannula; viewing via said endoscope; dissectingsurrounding tissue from the artery by moving a dissection tool along theartery; and removing a section of the artery.
 6. A method of harvestinga section of an artery from a body comprising the following steps:providing a blunt dissector having a lumen and an endoscope insertedinto said lumen; inserting said blunt dissector through an incision inthe body; advancing said blunt dissector alongside the artery to bluntlydissect with said blunt dissector to create a space in body tissue, thespace being at least partially occupied by said blunt dissector; viewingvia said endoscope; providing a dissection tool separate from said bluntdissector; and dissecting surrounding tissue from the artery by movingthe dissection tool along the artery.
 7. A method of harvesting asection of an artery from a body comprising the following steps:providing a tunneling member having a lumen and an endoscope insertedinto said lumen; inserting said tunneling member through an incision inthe body; advancing said tunneling member alongside the artery todissect with said tunneling member to create a space in body tissue, thespace being at least partially occupied by said tunneling member;viewing via said endoscope; providing a dissection tool separate fromsaid tunneling member and dissecting surrounding tissue from the arteryby moving the dissection tool along the artery.
 8. A method ofharvesting an artery from a body comprising the following steps:providing a dissection cannula having a lumen; inserting an endoscopeinto said lumen of said dissection cannula; inserting said dissectioncannula through an opening in the body and positioning the dissectioncannula adjacent the artery; advancing said dissection cannula along theartery to create a space in body tissue, the space being at leastpartially occupied by said cannula; monitoring the advancing of saiddissection cannula via said endoscope; removing said dissection cannulafrom the body; retracting the space to create a working space; insertinga trocar into the body; inserting a dissection tool through said trocarinto the working space; and moving the dissection tool along the bloodvessel to separate the artery from surrounding tissue.
 9. The method ofclaim 8 wherein said step of retracting the space comprises the step ofinserting an insufflation port into the body and insufflating the spacevia said insufflation port.
 10. The method of claim 8 further comprisingthe steps of inserting an endoscope into the working space andmonitoring the moving of the dissection tool along the artery.
 11. Themethod of claim 8 wherein said dissection cannula has an inflatablemember disposed on a distal portion of said dissection cannula.
 12. Themethod of claim 11 further comprising the step of inflating saidinflatable member.
 13. The method of claim 8 wherein said trocar isinserted into the body after the step of removing said dissectioncannula.
 14. The method of claim 8 wherein said trocar is inserted intothe body prior to the step of inserting said dissection cannula.
 15. Themethod of claim 8 wherein said dissection tool comprises an elongate rodhaving a hook disposed on a distal end of said rod.
 16. The method ofclaim 8 wherein the step of inserting the dissection cannula into thebody adjacent the artery and advancing said cannula along the arterycreates a space which is occupied entirely by the cannula.
 17. Themethod of claim 8 wherein the step of removing said dissection cannularesults in a space occupied by body tissue.
 18. The method of claim 8wherein said step of inserting said endoscope into said lumen of saiddissection cannula is performed prior to inserting said dissectioncannula through an opening in the body.